1. Technical Field
The present invention relates to an earphone that can reduce pressure in the ear canal and provide enhanced sound quality. More particularly, the invention relates to an earphone with an air channel passing through the earphone body so that acoustic waves reflected by the eardrum while the earphone is in use can propagate out of the ear canal through the air channel to reduce pressure in the ear canal and thereby contribute to an enhancement in sound quality.
2. Description of Related Art
The conventional earphones, as disclosed in Taiwan Utility Model Patent No. M517497, entitled “Speaker Unit and Earphone”, and Taiwan Utility Model Patent No. M529998, entitled “Earphone with Moving-Coil Piezoelectric Dual-Frequency Speaker”, typically include a loudspeaker provided in a closed receiving space, wherein the loudspeaker can vibrate a vibrating membrane in order for the resulting acoustic waves to propagate to the eardrum to make sound.
The prior art earphones, however, have the following drawbacks during use:
1. When an earphone is worn in/on/around the ear, the ear canal is blocked by the earphone and turned into a closed space, in which acoustic waves generated by the vibrating membrane travel back and forth between the earphone and the eardrum, causing abnormal pressure on the eardrum and consequently a sense of discomfort.
2. The acoustic waves propagating to and fro in the ear canal also generate a compressive force on the vibrating membrane such that acoustic waves subsequently generated by the vibrating membrane are compromised, resulting in distortion of sound, especially in the medium- to high-frequency range.